Geared pitman



25, c. O'LEARY 2,294,993

I GEARED- PITMAN Filed Dec. 9, 1940 z INVENTOR Charles 7 7. Glad/y ATTORNEY Io BY /8 Patented Aug. 25, 1942 UETED STATES PATENT OFFICE 13 Claims.

The present invention relates generally to what are commonly known as oil Well pumping units, and more particularly to the type of pumping unit most frequently found in practise, in which pitmans are used in connection with gear units for the conversion of speedy rotation of a motor, internal combustion engine, or other suitable source of power, and its transmittal in the form of slow reciprocation to a Walking beam, from one end of which connection is made to the pump rod of a well.

In pumping units of the above character, the speed reducing gear units, cranks and widely spaced apart pitmans with equalizing connections to the Walking beam, are all features which enter very materially into the cost of the pumping unit as a whole, a cost which it is the primary object of the present invention to greatly reduce through the elimination of certain of said features and the combining of the functions of others.

More specifically, it is an object of the present invention to provide a geared pitman which, in its attachment to the walking beam of a pumping unit, avoids the necessity of an expensive equalizing connection to the beam, essential in a unit having pitmans in widely spaced apart relation.

It is well known that in the pumping units of the above type, two pitmans are widely spaced apart by reason of their extension from crank arms situated in widely spaced apart relation beyond opposite sides of a reducing gear or gear unit which is generally of considerable width. It is proposed to substitute a single pitman in an arrangement eliminating the usual gear unit and crank arms.

A further object of the invention is thus to provide a geared pitman which will combine the functions of the present pitmans and gear unit and will in this respect greatly reduce the cost of the present gear unit, cranks and pitmans which it replaces.

A still further object is the provision of a geared pitman which will provide for ready, inexpensive connection with the walking beam, either directly or through a down bar, and is directly actuated by a high speed pinion in a manner to bring about slow reciprocation and entirely replace the gear unit, crank shaft, crank arms, pitmans and equalizing connections of the present pumping units.

With the above general objects in mind, the further objects of the invention, together with the resulting advantages, will clearly appear in the course of the following description in detail of a form of the invention at present preferred for carrying the same into practical aifect. This example of the invention is shown in the accompanying drawing, which forms a part of this specification, and in which,

Figure 1 is a side elevation of a well pumping unit embodying the present improvements.

Figure 2 is an enlarged side view of thepitman and a portion of the down bar, certain parts being broken away and in section.

Figures 3 and 4 are enlarged detail vertical sectional views through portions of the pitman, taken respectively on lines 33 and 44 of Figure 2.

Figure 5 is a partial section, along the line of Figure 4, showing a slightly modified arrangement.

Referring now to these figures, and particular-- ly to Figure 1, there is shown portions of the usual pumping unit, including a sampson post In, suitably braced in the unit, and a walking beam I I having a working fulcrum I2 on said post, and also having a horse head I3 at one end which, in practise, is connected by suitable reins or other means, to a polish rod clamp of a well pump so that vertically oscillating movements of the beam will cause vertically reciprocating movements of the pump rod.

The beam I I is shown as provided with a rigid and braced down bar I l, and for the purposes of the present disclosure, this down bar has been shown in Figure 2 with a lengthwise series of openings I5, intermediate its ends, providing for the adjustable connection of a bearing block I6 to the down bar.

The pitman of the present invention, generally indicated at [1, comprises a pair of side elements or members I8, tapering in width from relatively wide, concavely recessed outer ends, to relatively narrow opposite or inner ends at which they are pivotally connected to the bearing block I6. These side members I8 have their said concavely recessed ends formed to seat against, and partially around, the outer peripheral surface of an enlarged, shaftless ring gear I9, and fiatwise along opposite sides of an external annular rib 2D with which the ring gear is provided at a median line, as most plainly seen by reference to Figures 3 and 4. To this rib 20 the side members I3 are rigidly secured by bolts 2I which extend laterally into the rib at spaced points along the concavely recessed ends of the pitman members.

The gear llllg I9 thus forms a part of the pitman at its larger or wider end, and serves as a rigid brace and connection for the pitman side members IS, the latter of which may, of course, be additionally braced and connected to each other along the intermediate portions thereof if it is found to be desirable or necessary to do so.

The gear ring l9 has laterally outstanding side flanges 22 at opposite sides of, and outwardly be-- yond, its inner internally toothed or geared ring 23, and the inner faces of these flanges form bearing surfaces in relation to the peripheral edges or edge portions of a pair of supporting side discs 24.

The side discs 24 are rigidly connected and braced in definitely spaced apart relation by connecting bolts 25 extending through the discs and through the otherwise open central portion of the shaftless gear ring [9, and around which bolts spacing thimbles 26 are disposed between the discs, so that the latter are in movable bearing relation at their peripheral portions with the inner bearing surfaces of the flanges 22 and also with the side surfaces of the inner toothed ring 23.

The above described relative disposition of parts is plainly shown in Figures 3 and 4, and from Figure 3 it will be noted that at one point the discs 24 are laterally enlarged and apertured, opposite to each other adjacent to their peripheries, as at 21, forming bearings through which a high speed shaft 23 is journaled. On this shaft a pinion 29 is keyed or otherwise fixed between the side discs 24, and in meshed relation with the toothed inner ring 23 of the ring gear.

Laterally beyond the ring gear E9, the shaft 23 may be suitably supported as, for instance, in journal members 39 on supporting frames 3|, the shaft being shown as having at one end a grooved pulley 32 for belt connection to a suitable source of power, for example, an electric motor or an internal combustion engine.

Since the high speed shaft 28 has its journals in the side discs 24, and the latter form the sole direct support of the ring gear [9, the action of the parts is plainly that of an eccentric, the discs swinging about the axis of shaft 28 as the toothed ring 23 crawls around the pinion 29, to shift the pitman l1 lengthwise for the slow reciprocation of its beam actuating end.

Furthermore, since the above is true, and the ring gear and discs are circular and in continuous, uniform peripheral bearing contact at all times, the pinion 29 will be definitely positioned with relation to the toothed ring 23 of the ring gear, and thus definitely alined with, and across, said toothed ring, with the additional advantage that the desired depth of mesh of the engaging teeth may be established in the first instance and thereafter uniformly maintained.

It is important to note that the side discs 24, in addition to acting as a bearing support for the ring gear I9, close the opposite sides of said gear and thus form within the latter a closed oil reservoir, whereby a plentiful supply of lubricating oil may be maintained throughout long periods constantly in direct contact with the toothed ring 23 and the pinion 29.

The bearings 21 of the side discs 24 are, for the above reason, provided with oil seal grooves and rings 33 around shaft 28, in addition to, and outwardly beyond, any desirable anti-friction means 34. The peripheral surfaces of the discs 24 also preferably have oil seal grooves and rings 35 in contact with the inner bearing surfaces of the ring gear flanges 22, although this particular arrangement may be Varied, as shown in Figure 5, by having the discs provided with offset annulerly outstanding flanges 36 so that the bearing engagement of the discs with the ring gear is the same as previously described and, in addition thereto, the discs have their flanges 36 in bearing contact with the side or edge surfaces of the ring gear flanges 22.

In the event the annularly overlapping flanges 35 are used as in Figure 5, oil seal grooves and rings 3'! may be provided in the side or edge surfaces of the ring gear flanges 22. In any event the lubricating oil in the reservoir of the ring gear will be held against leakage, and the toothed engaging parts will thus run in a bath of oil so that wear will be reduced to a minimum.

Having thus fully described my invention, what I claim is:

1. In a speed reducing drive for pumping units, a pitman, a drive shaft, a reducing gear including gear members, one of which is carried by the shaft, and the other of which is a shaftless ring gear carried by the pitman and is eccentrically shiftable around the shaft gear with the gear members in mesh, and rotatable members forming side closures for said ring gear and in peripheral bearing relation uniformly around the ring gear.

2. In a speed reducing drive for pumping units, a pitman, a drive shaft, and a reducing gear including gear members, one of which is carried by the shaft, and the other of which is an internally toothed, shaftless ring gear rigidly connected to, and forming a part of, one end of the pitman, and means closing the sides of said pitman gear and constraining the same to move bodily around the shaft gear and in uniform engagement therewith.

3. In a speed reducing drive for pumping units, a pitman, a drive shaft, a reducing gear including gear members, one of which is carried by the shaft, and the other of which is a rigid part of the pitman and in the form of an internally toothed shaftless ring gear for movement eccentrically around the shaft gear in mesh therewith, and members journalled to swing about the axis of the shaft and in peripheral rotative bearing engagement with the pitman gear, forming a guide and bearing for the pitman gear in its eccentric movements.

4. In combination, a drive shaft having a pinion, a pitman having a hollow gear ring at one end thereof provided with teeth internally thereof in mesh with the pinion of the shaft, and guide means for maintaining the ring and pinion uniformly in mesh, consisting of side members eccentrically journalled to swing around the axis of the pinion shaft and in uniform, peripheral bearing with, and around, the ring gear.

5. In combination, a drive shaft having a pinion thereon, a pitman having a shaftless, internally toothed ring gear at one end around, and in mesh with, the shaft pinion, and means eccentrically journalled to rotate around the axis of the shaft and peripherally in rotatable bearing contact with the ring gear to thus form a bearing guide for the pitman gear in its movements around the shaft.

6. In combination, a drive shaft having a pinion thereon, a pitman having a shaftless, internally toothed ring gear fixed at one end thereof around, and in mesh with, the shaft pinion, and members journalled to rotate eccentrically around the axis of said shaft, having peripheral bearing contact with the pitman gear entirely therearound at its opposite sides, holding the gears in constant, uniform mesh.

7. A pitman having at one end thereof an internally toothed, shaftless ring gear, discs at opposite sides of, and in peripheral bearing relation with, said ring gear for supporting and guiding the latter, a shaft journalled through said discs and having thereon a pinion. in mesh with the internal teeth of the gear of the pitman, and supporting and driving means for said shaft.

8. A pitman, an internally toothed, shaftless ring gear rigidly in connection with said pitman at one end thereof, a pair of side discs in peripheral bearing contact with the ring gear at its opposite sides and rigidly in connection with each other through the space within the ring gear, and a shaft journalled through the discs and having a pinion in mesh with the teeth of the ring gear.

9. A pitman, a drive shaft having a pinion thereon, an internally toothed, shaftless ring gear at one end of the pitman around, and in mesh with, the shaft pinion, and a pair of side discs through which the shaft is journalled, said discs being in rotatable contact at their peripheral portions with the ring gear at opposite sides of the latter and in rigid connection with each other through the space internally of the ring gear, and said discs being otherwise imperforate for completely closing the said space within the ring gear and forming an oil reservoir within the latter.

10. A pitman, a drive shaft having a pinion thereon, an internally toothed, shaftless ring gear at one end of the pitman around, and in mesh with, the shaft pinion, a pair of side discs in peripheral rotatable contact with opposite sides of the ring gear, and through which the shaft is journalled, said discs being in rigid connection with each other and closing the space within the ring gear in a manner to form an oil reservoir in said gear, and oil seal grooves and rings in the rotatable bearing surfaces between the said discs and the ring gear and shaft.

11. In combination, a drive shaft having a pinion thereon, a pitman having a shaftless, internally toothed ring gear fixed at one end thereof around, and in mesh with, the shaft pinion, members journalled to rotate eccentrically around the axis of said shaft, having peripheral bearing contact with the pitman gear entirely therearound at its opposite sides, holding the gears in constant, uniform mesh, and means rigidly connecting said side members to laterally confine the ring gear and close the space therein.

12. A pitman, a drive shaft having a pinion thereon, an internally toothed, shaftless ring gear at one end of the pitman around, and in mesh with, the shaft pinion, a pair of solid discs in peripheral rotatable contact with opposite sides of the ring gear, and eccentrically journalled to rotate around the axis of the pinion shaft, means extending through the space within the ring gear and rigidly connecting the said discs to close the sides of said space for forming an oil reservoir therein, and oil seal means in the rotatably contacting surfaces of the ring gear and side discs.

13. A pitman, an internally toothed ring ear fixed at one end of said pitman, a pinion shaft extending through said ring gear, a pinion on the shaft in mesh with the gear, and side members journalled to swing about the axis of said shaft, said members being in peripheral bearing relation uniformly with the ring gear and completely closing the opposite sides of said gear.

CHARLES M. OLEARY. 

